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authorTom Rondeau <trondeau@vt.edu>2013-04-17 13:43:52 -0400
committerTom Rondeau <trondeau@vt.edu>2013-04-29 14:52:56 -0400
commitf3e2e07201c50033bf6c9d0c6a6f068557b4f17f (patch)
tree140b3c2d20a951ffd4abd564c3378ee2e2f9fc7c /gnuradio-runtime/lib/vmcircbuf_mmap_shm_open.cc
parent35303ae975a5b1bdecc2492bc96e2b8e89b62a3d (diff)
runtime: converting runtime core to gr namespace, gnuradio include dir.
Diffstat (limited to 'gnuradio-runtime/lib/vmcircbuf_mmap_shm_open.cc')
-rw-r--r--gnuradio-runtime/lib/vmcircbuf_mmap_shm_open.cc204
1 files changed, 204 insertions, 0 deletions
diff --git a/gnuradio-runtime/lib/vmcircbuf_mmap_shm_open.cc b/gnuradio-runtime/lib/vmcircbuf_mmap_shm_open.cc
new file mode 100644
index 0000000000..7b461bc26b
--- /dev/null
+++ b/gnuradio-runtime/lib/vmcircbuf_mmap_shm_open.cc
@@ -0,0 +1,204 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2003,2011,2013 Free Software Foundation, Inc.
+ *
+ * This file is part of GNU Radio
+ *
+ * GNU Radio is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3, or (at your option)
+ * any later version.
+ *
+ * GNU Radio is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GNU Radio; see the file COPYING. If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "vmcircbuf_mmap_shm_open.h"
+#include <stdexcept>
+#include <assert.h>
+#include <unistd.h>
+#include <fcntl.h>
+#ifdef HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+#ifdef HAVE_SYS_MMAN_H
+#include <sys/mman.h>
+#endif
+#include <errno.h>
+#include <stdio.h>
+#include "pagesize.h"
+#include <gnuradio/sys_paths.h>
+
+namespace gr {
+
+ vmcircbuf_mmap_shm_open::vmcircbuf_mmap_shm_open(int size)
+ : gr::vmcircbuf(size)
+ {
+#if !defined(HAVE_MMAP) || !defined(HAVE_SHM_OPEN)
+ fprintf(stderr, "gr::vmcircbuf_mmap_shm_open: mmap or shm_open is not available\n");
+ throw std::runtime_error("gr::vmcircbuf_mmap_shm_open");
+#else
+ static int s_seg_counter = 0;
+
+ if(size <= 0 || (size % gr::pagesize ()) != 0) {
+ fprintf(stderr, "gr::vmcircbuf_mmap_shm_open: invalid size = %d\n", size);
+ throw std::runtime_error("gr::vmcircbuf_mmap_shm_open");
+ }
+
+ int shm_fd = -1;
+ char seg_name[1024];
+ static bool portable_format = true;
+
+ // open a new named shared memory segment
+ while(1) {
+ if(portable_format) {
+
+ // This is the POSIX recommended "portable format".
+ // Of course the "portable format" doesn't work on some systems...
+
+ snprintf(seg_name, sizeof(seg_name),
+ "/gnuradio-%d-%d", getpid(), s_seg_counter);
+ }
+ else {
+
+ // Where the "portable format" doesn't work, we try building
+ // a full filesystem pathname pointing into a suitable temporary directory.
+
+ snprintf(seg_name, sizeof(seg_name),
+ "%s/gnuradio-%d-%d", gr::tmp_path(), getpid(), s_seg_counter);
+ }
+
+ shm_fd = shm_open(seg_name, O_RDWR | O_CREAT | O_EXCL, 0600);
+ if(shm_fd == -1 && errno == EACCES && portable_format) {
+ portable_format = false;
+ continue; // try again using "non-portable format"
+ }
+
+ s_seg_counter++;
+
+ if(shm_fd == -1) {
+ if(errno == EEXIST) // Named segment already exists (shouldn't happen). Try again
+ continue;
+
+ char msg[1024];
+ snprintf(msg, sizeof(msg), "gr::vmcircbuf_mmap_shm_open: shm_open [%s]", seg_name);
+ perror(msg);
+ throw std::runtime_error("gr::vmcircbuf_mmap_shm_open");
+ }
+ break;
+ }
+
+ // We've got a new shared memory segment fd open.
+ // Now set it's length to 2x what we really want and mmap it in.
+ if(ftruncate(shm_fd, (off_t)2 * size) == -1) {
+ close(shm_fd); // cleanup
+ perror("gr::vmcircbuf_mmap_shm_open: ftruncate (1)");
+ throw std::runtime_error("gr::vmcircbuf_mmap_shm_open");
+ }
+
+ void *first_copy = mmap(0, 2 * size,
+ PROT_READ | PROT_WRITE, MAP_SHARED,
+ shm_fd, (off_t) 0);
+
+ if(first_copy == MAP_FAILED) {
+ close(shm_fd); // cleanup
+ perror("gr::vmcircbuf_mmap_shm_open: mmap (1)");
+ throw std::runtime_error("gr::vmcircbuf_mmap_shm_open");
+ }
+
+ // unmap the 2nd half
+ if(munmap ((char *) first_copy + size, size) == -1) {
+ close(shm_fd); // cleanup
+ perror("gr::vmcircbuf_mmap_shm_open: munmap (1)");
+ throw std::runtime_error("gr::vmcircbuf_mmap_shm_open");
+ }
+
+ // map the first half into the now available hole where the
+ // second half used to be.
+ void *second_copy = mmap((char*)first_copy + size, size,
+ PROT_READ | PROT_WRITE, MAP_SHARED,
+ shm_fd, (off_t)0);
+
+ if(second_copy == MAP_FAILED) {
+ close(shm_fd); // cleanup
+ perror("gr::vmcircbuf_mmap_shm_open: mmap (2)");
+ throw std::runtime_error("gr::vmcircbuf_mmap_shm_open");
+ }
+
+#if 0 // OS/X doesn't allow you to resize the segment
+
+ // cut the shared memory segment down to size
+ if(ftruncate(shm_fd, (off_t)size) == -1) {
+ close(shm_fd); // cleanup
+ perror("gr::vmcircbuf_mmap_shm_open: ftruncate (2)");
+ throw std::runtime_error("gr::vmcircbuf_mmap_shm_open");
+ }
+#endif
+
+ close(shm_fd); // fd no longer needed. The mapping is retained.
+
+ if(shm_unlink(seg_name) == -1) { // unlink the seg_name.
+ perror("gr::vmcircbuf_mmap_shm_open: shm_unlink");
+ throw std::runtime_error("gr::vmcircbuf_mmap_shm_open");
+ }
+
+ // Now remember the important stuff
+ d_base = (char*)first_copy;
+ d_size = size;
+#endif
+ }
+
+ vmcircbuf_mmap_shm_open::~vmcircbuf_mmap_shm_open()
+ {
+#if defined(HAVE_MMAP)
+ if(munmap (d_base, 2 * d_size) == -1) {
+ perror("gr::vmcircbuf_mmap_shm_open: munmap (2)");
+ }
+#endif
+ }
+
+ // ----------------------------------------------------------------
+ // The factory interface
+ // ----------------------------------------------------------------
+
+ gr::vmcircbuf_factory *vmcircbuf_mmap_shm_open_factory::s_the_factory = 0;
+
+ gr::vmcircbuf_factory *
+ vmcircbuf_mmap_shm_open_factory::singleton()
+ {
+ if(s_the_factory)
+ return s_the_factory;
+
+ s_the_factory = new gr::vmcircbuf_mmap_shm_open_factory();
+ return s_the_factory;
+ }
+
+ int
+ vmcircbuf_mmap_shm_open_factory::granularity()
+ {
+ return gr::pagesize();
+ }
+
+ gr::vmcircbuf *
+ vmcircbuf_mmap_shm_open_factory::make(int size)
+ {
+ try {
+ return new vmcircbuf_mmap_shm_open(size);
+ }
+ catch (...) {
+ return 0;
+ }
+ }
+
+} /* namespace gr */
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